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Collection Conservation

Introduction | Essay | Paintings | Paper | Preventive | Textiles

 

Frequently asked questions

  1. How do I best care for my painting at home?
  2. How can I care for my painting and keep it looking fresh?
  3. How do I store my textiles?
  4. Why is my bark painting bowed? Can anything be done about it?
  5. What can be done about flaking paint on my bark painting?
  6. Effects of light levels on works of art, or 'Why has the green grass in my watercolour turned brown?'
  7. Can I repair my work of art on paper?
  8. Why does paper become brown and stained?

The following recommendations are intended as guidance only, and the Conservation Department of the National Gallery of Australia does not assume any responsibility or liability.

1. How do I best care for my painting at home?

Paintings come in many forms: they can be on canvas, cardboard, hardboard, Masonite, metal, glass, wood panel and even corrugated iron etc. In addition, the paint itself can be oil, acrylic, house paint, watercolour, egg tempera, distemper, sand, chalk, dry pigments.

So, it helps if you know a little about what your painting is made from, particularly whether it's a canvas or panel, oil or acrylic. A qualified conservator can easily identify the material for you.

Generally, paintings should be protected from heat, sunlight, bright indoor lighting, water, physical vibration and dust.

We recommend that all paintings in the home should be kept:

2. How can I keep my painting safe and looking fresh?

3. How do I store my textiles?

Textiles are fragile items and are adversely affected by light, temperature, humidity, insects and poor handling. These factors lead to fading, creasing, fibre deterioration, holes and mould growth. Good housekeeping, combined with correct storage methods and archival materials will help your textiles survive for generations to come.

Excluding light, dust, moisture and insects is vital. The optimum storage conditions for textiles are
18-22°C, 50-55% RH, however stability is more important than maintaining exact levels. Do not store textiles in areas with large temperature fluctuations, i.e. near a heater, or dryer. Humidity over 60% increases the potential for mould growth.

Flat textiles should be stored rolled on acid free cardboard tubes, 10 cm or more in diameter with acid free tissue interleaving. Costumes, heavily embroidered or appliquéd, textured pieces, should be stored in drawers or boxes large enough to allow the item to be laid out, with as few folds as possible.

Crumpled acid free tissue or padded wadding rolls can be used to support all pleats and folds.

All stored textiles should be regularly checked for insects, at the beginning of spring and the end of summer.

At the same time, checks for mould or moisture should be carried out and any discoloured and collapsed tissue or padding should be replaced.

With the storage of very fragile textiles it may be advisable to consult a Textile Conservator.

4. Why is my bark painting bowed? Can anything be done about it?

It is natural for a piece of bark to be bowed. Bark, once removed from the living tree, undergoes complex changes. Warping and buckling are the visible effects of gradual movements, the natural tendency of bark to revert back to its original, cylindrical shape. Any attempts to prevent these natural movements have no lasting effects. Forced flattening of a distorted bark or excessive use of restraining mechanisms may cause a build-up of stresses, potentially leading to serious splitting.

5. What can be done about flaking paint on my bark painting?

The paint layer on Australian Aboriginal bark paintings, both old and new, is frequently very fragile due to flaking paint. This is caused by several factors including the nature of pigments used, the binding media, and the bark that was chosen as the support for the painting.

Flaking paint can be successfully treated in most cases by an experienced conservator, using local consolidation techniques. The exact type of treatment and consolidant is dependent upon the individual bark painting and cannot be determined without closely examining the object.

The aim of such conservation treatment is to stabilise the condition of the painting with minimal interference with its original qualities. Since consolidation of friable paint layers cannot be removed or reversed without damaging the painting, the issue of the long-term stability of the consolidant is very significant.

Many treatments have been tried in the past, including local consolidation as well as overall spraying of the whole surface with various resins. Overall treatments were particularly unsuccessful. Some common, undesirable side effects of spraying include severe colour change, darkening, and shininess of the surface.

Commercially available fixatives should never be sprayed on bark paintings for the reasons outlined above.

6. Effects of light levels on works of art, or 'Why has the grass in my watercolour turned brown?'

Museums and art galleries around the world have agreed that all exhibits need to be lit according to certain standards. This is because light is a type of energy which can interact with most materials and just as human skin can burn from too much sun exposure, so too can works of art be damaged.

Our bodies can repair themselves, but when a work of art is damaged by light the damage is permanent; it can never be undone.

In order to minimise light damage in art objects, museums specify light intensity levels which are low enough to slow down deterioration, but still bright enough for viewing. They also limit the display time because light damage is cumulative.

At home light damage can't be controlled or monitored as well, and museum limits are a bit meaningless, but the general idea can be followed. Basically, it is best to keep light levels as low as you can on displayed items, and to screen out as much ultra violet (UV) light as possible.

The green rolling hills which Granny saw in her Irish watercolour landscape have become dull and brown. Your kids now think that the Emerald Isle looks more like the back of Cooma in December.

This type of damage occurs because one component of the paint used has faded more than another and was light sensitive.

In addition, it is likely that the complete image has yellowed and discoloured due to light exposure. Watercolours, paints and the supporting materials used such as paper and canvas react and fade at different rates. Generally speaking, red colours, yellows and some blues are most at risk, as are natural dyes. The yellow component of the watercolour used in Granny's green grass has faded away, leaving the other colours it was mixed with still visible - probably brown and blue.

7. Can I repair my work of art on paper?

For conservation materials see Conservation Suppliers.

8. Why does paper become brown and stained?

One of the most common causes of discolouration and staining of paper is contact with acidic or chemically unstable materials, combined with the effects of light, heat and moisture. The culprit is usually woodpulp cardboard or wooden backing material used to mount and frame works on paper. The cardboard may be recognised by a characteristic dark tone at the cut edge of the window mount, and often by a discolouration of the paper near the point of contact. Other stains may be caused by the ageing of adhesives such as pressure sensitive tapes, or mould stains. Foxing, brown spot stains, can develop as a result of metallic impurities and micro-organisms in the paper. These forms of discolouration generally indicate the paper is becoming acidic and should be treated, or isolated from the damaging environment.